This invention relates generally to treadles as may generally be used in roadways to sense vehicular traffic flow; this invention is more particularly directed to such treadles designed to be repaired or replaced without great expenditure of manpower or materiel resources.
Conventional treadle assemblies generally comprises a rubber treadle envelope containing a plurality of contact strips arranged to actuate a counter, thereby providing a record of the passage of vehicles over a predetermined section of the roadway. Typical such treadles are shown, e.g., in U.S. Pat. Nos. 2,761,928; 2,251,351; and 2,165,227.
Treadles have been generally utilized for counting of vehicular traffic and are conventionally disposed transversely on a roadway lane so that vehicles travelling in that lane must pass over the treadle. Quite often section of roadway occupied by the treadle may be at a toll plaza where a vehicle driver must slow down or stop and maneuver his vehicle to a toll booth, pay the required toll, and then accelerate to merge into the traffic on the toll facility, which may be a bridge, expressway, tunnel, or the like.
Treadles located at such installations have been subjected to excessive wear oweing to the traffic conditions associated therewith, and as a result of the vehicles' repeatedly rolling over the same portions of the treadles. As a result, the rubber envelope and contact strips contained therein must be replaced rather frequently.
It is the general practice to replace the entire treadle assembly as soon as the rubber envelope begins to show signs of significant wear, even though perhaps only a single pair of the contact strips may be affected by the wear. Also, the treadle assembly is rather cumbersome and massive, and replacement thereof requires the efforts of several workers for a period of up to a few hours.